RESILIO — Amsterdam's Smart Blue-Green Roofs Networked to Weather Forecasts (Netherlands)

RESILIO (Resilient Cities Implementing Large-scale Integrated Operations) ran from November 2018 to April 2022 under the EU Urban Innovative Actions programme. The City of Amsterdam led it with Waternet, technology provider Metropolder, scientific partners including Vrije Universiteit Amsterdam, and the NGO Rooftop Revolution.
The project installed more than 10,000 m² of blue-green roofs on housing-association and privately owned buildings (the latter through a municipal grant scheme), exceeding its 10,000 m² target. Roofs store rain and are remotely networked: using weather forecasts, storage is emptied beforehand when intense rain is expected, lowering peak flow to the sewer. The UIA describes it as the largest demonstrator of its kind.
Reported results are mostly qualitative: reduced runoff during heavy rain at key locations, and an impact study suggesting an upscaled programme could significantly reduce district-scale flooding. No peak-reduction percentage was verified here. The UIA states a single roof has negligible district-level heat impact, so cooling needs scale-up.
Cautions: procurement brought cost and specification uncertainty; costs and benefits fall on different stakeholders so a funding business model remained unresolved; Covid-19 hampered citizen engagement; and biodiversity was added later rather than designed in from the start. Monitoring data fed a cost-benefit case for future Amsterdam roofs.

Read the full analysis: https://openresearch.amsterdam/en/page/83617/resilio-final-report